Electric connecting device



1954 E. P. G. WRIGHT ELECTRIC CONNECTING DEVICE Filed Sept. 25 1951 3 Sheets-Sheet 1 nag E. R6. WRIGHT Attorney Jan. 26, 1954 3 Sheets-Sheet 2 Filed Sept. 25 1951 E P.G.WPIGHT Atlorn Jan. 26, 1954 wRlGHT 2,667,542

ELECTRIC CONNECTING DEVICE Filed Sept. 25, 1951 s Sheets- Sheet a /nput K I I I cc a FIGS.

A Horn e y Patented Jan. 26, 1954 ELECTRIC CONNECTING DEVICE Esmond Philip Goodwin Wright, London, England, assignor to International Standard Electric Corporation, New York, N. Y., a corporation of Delaware Application September 25, 1951, Serial No. 248,196

Claims priority, application Great Britain September 26, 1950 7 Claims.

This invention relates to static switching devices, and consist broadly in means for making an electrical connection by static coupling.

While the invention is applicable to coupling between a single pair of circuits it is also applicable to switches in which alternative connection possibilities exist between different pairs of a number of circuits, for instance, switches of the type used in telecommunication switching systems, and it is particularly suitable for application to co-ordinate switches, in connection with which the invention will be described.

It is an object of the present invention to provide such a switch in which any one of a plurality of input circuits can be coupled to any one of a plurality of output circuits without any direct metallic connection being established be tween the circuits coupled together.

The invention will now be described with reference to the accompanying drawings, in which;

Fig. l is a diagrammatic representation of means according to the present invention for establishing a connection between a single input circuit and a single output circuit;

Fig. 2 is a flattened-out diagrammatic representation of a multi-switch according to the present invention;

Fig. 3 is a perspective diagrammatic representation of a multi-switch according to the present invention;

Fig. 4 is an enlarged fragmentary view of part of Fig. 3; and

Figs. 5 and 6. show modifications of the means shown in Fig. 1.

In Fig. l, I is an input speech coil and 2 is an output speech coil. The input coil I is wound on a core formed by part of a loop 3 of a magnetic material having a very low value of remanence. Thereforeany current variations dueto an A. C. flow in the coil I willproduce a varying magnetic flux in its core. Although this core is in the form of closed loop 3 it is shown as a straight bar for convenience of representation. The output speech coil 2 is wound on a similar loop 4 of magnetic material, also shown as a straight bar.

The loops 3 and 4 are so arranged that they are adjacent at point 5, at any desired angle, although parallelism is considered to give optimum results. A coil 6 is mounted on the two loops in such a way that it embraces the loops at point 5.

If the coil I is energised with an alternating current in the speech range the varying magnetic flux induced thereby in the loop 3, part of which forms an iron core for coil I, will have some influence on the magnetic state of loop 4 since the loops are in close proximity at the crossover point 5. However, under normal conditions the magnitude of this transfer of magnetism is so small as to be practically negligible. It has been found that if the coil 5 which embraces the loops 3 and t at the crossover point 5 is energised with radio frequency current, preferably in the range 20 kc./s. to 200 kc./s., the magnetic transfer is greatly facilitated. The frequency of the coupling current may be within quite wide limits, the limit being set by the magnitude of the A. C. circuit impedance. In fact, the magnitude of the effect becomes so great that there is produced in the loop 4 a varying magnetic flux whose amplitude is almost equal to the amplitude of the varying magnetic flux in the input loop 3. This varying flux in loop 4 will, in the normal manner, induce into the output coil 2 a varying current whose amplitude will almost equal the amplitude of the original current flowing in the coil I.

Therefore it is possible to establish a connectionbetween input and output circuits without any direct metallic connection.

Fig. 2 shows a co-ordinate multi-switch according to the present invention in which loops HI to HIO (shown as straight bars) bear input coils II to Ill) respectively and loops VI to VII) (shown as straight bars) bear output coils OI to OIO respectively. Each crossing point between one of loops HI to HIO and one of loops VI to VI 0 is embraced by a coil such as I-IVI I or I-IV99. A speech path can be established between any input coil and any output coil by applying the radio frequency to the coil embracing the crossing point of the loops on which the desired input and output coils are wound. Thus, for example, to establish connection for speech between coil 12, wound on loop H2, and coil 02, wound on loop V2, the coil I-IV22 is energised with R. F. by switching means not shown. Magnetic transfer between these loops will then become almost complete, so that the speech circuit has become effectively extended through the switch.

Selection of the coil required to establish the desired speech path connection can be performed by any known method of selection, one such as by using combinations of cold cathode gaseous discharge tubes or conventional relay systems. Supervisory and control signals which are normally passed through the switching circuit over a third wire can be converted into V. F. signals and then sent in well-known manner over the speech circuit. Alternatively, a separate switch- 3 ing circuit of any desired type can be provided to cater for the third wire.

Fig. 3 shows in perspective a diagrammatical view of a. multi-switch according to the invention having three input coils II, I2 and I3 wound on three loops HI, H2 and H3 respectively. Three output coils Ol, 02 and 03 are wound on three loops Vi, V2 and V3 respectively. These loops, as before, are formed'of a magnetic material having a low value of remanence. The crossing points between loops are embracedby coils HV! 1 to HV33.

Fig. 4 is a considerably enlarged view of one of the crossing points of the switch of Fig. 3.

In the switch according to Figs. 3 and 4, a speech path between any input coil and any output coil can be established by 'e'ne'rgising with R. F. the coil embracing the junction point of the loops on which the desired input ando'utput coils are mounted.

The switch :shownin Fig. -2 is preferably .ar-

ranged in the manner shown in Fig. 3,-i.- e. with the ten V loops disposed radially on the ten H loops which are axially aligned. The coupler 'coils can be arranged to embrace both wires of the V-loops if the windings are suitably phased asthe flux in the legs of the V loop will then be inopposition. The coils wound on the V loops :may if desired be used as input coils, in'which casezthecoils wound on the .H loops would obviously be output :coils.

Another arrangement is shown in Fig. 5 in which-input. and output .coilsIC, C are mounted on magnetic :cores MOI, 'MCZ having no particular physical :relati'on. .A coupling coil CC iswoundpartly aonione core, partly on the other.

When coil .CC is fed with alternating current,

for example of supersonic frequency, voice frequency currentszapplied to coil .10 are transferred The A. C. supply ma.-y:be applied :in any known manner :to allow coupling between :input and output circuits.

:With the arrangement shown in :Fig. there will nevertheless he a loss-due to th'e fac't that certain of the input energ'y will be dissipate'd in the coupling coil. This can be overcome by a combination'of opposing coils-as shown in Fig.6. Iwo series input coils I01, 162 are oppositely wound on two'magnetic cores MC-l MCZ having no particular tphysical relation. T-wo' outp'utcoils OCI OC2, a'r'e=also oppositely woundon the two cores, while the cores also "carry two "similarly wound coupling coils CCl 2 to which alternating current preferably of supersonic frequency is applied.

While the principles of the invention --have been described above in' confnection with specific embodiments and particular"modifications -th ere- ---'of, it -is to be clearly understood that "this de- .icircuits, one .coil forming an input circuit and the other coil forming an output circuit, and a third coil encircling portions of both said magnetic loops.

2. A device, as claimed in claim 1, comprising means for applying high frequency current to said third "coil.

3. ,A device,pas-claimed in claim 2, comprising two sets of alternating current magnetic loops,

all of which carry coils, and third coils encircling the corresponding magnetic loops of every possible pairing {of coils of the two sets, whereby alternating :frequency current can be transferred from any one alternating cur-rent coil of one set :to :any one alternating current coil of the other set.

l. A device, .as claimed in-claim :1, comprising one magnetic loop associatedwith 'a pluralityqof other magnetic loops iand an equal plurality of third coils, each encircling said one loop :ond one of the other loops.

5. A deviceyas claimediin claim A, and. in which each third coil :is in two portions, :separatel-y wound, one on :each *0f :the time :magnetic :loops associated with said 'third :coil.

6. A'device, as claimed in .claim .1, in which each transmission circuit comprises two 420115 oppositely wound "one on each (of said magnetic loops and in which said coupling coil comprises two parts similarly -wound one onreach of said magnetic loops.

7. A device for transferring communication currents from one transmission circuit to another, comprising two magnetic :loops, respectively encircled over portions of their lengths with coils formingipartsof-said-twotransmission circuits, one coil *formin g --an input circuit and theother coil forming an output circuit, and a third coil encircling portions of both 'said magnetic loops, said third" coil "being in two portions, separately woundf'one'on each of the two magnetic loops.

'ESMON'D PHILIP 'GI'OQDW-Ill 'WRIGHT.

References Citeil in the vfile :of this :pateni'.

UNITED STATES PATENTS Number Name Date 2,187,115 rEllwoodptal. ,Jan. -16, 194.0 2,446,033 wellings Jul-3 427, :1948 2 510,061 :Bransonetal. :June 6, .1850 2,580,082 Dim'ond Dec. 25, 195.1 

